They might have had plastic in the past but that was also back when the machining technology wasn't available to produce such low tolerance metal casings. Apple has phased out all plastics casings from their products, why would they reintroduce it? There is also a big difference between a plastic low end iPhone and a "low end" Mac Pro. The "low end" Mac Pro was still very powerful and still looked like a Mac Pro.

A plastic iPhone would be a 5 year step backwards.

Notice these "iPhones" don't have any of the license information or product model info printed on them at all. If they took the time to print the word iPhone then why didn't they also print that on the casing?

Plastic technology has also vastly improved in the last 10 years, even the last 3 years.

Also it won't be a "cheap" phone, it will be better than a 4s and free on subsidized markets, and cheaper than the 4s for unsubsidized customers. It's a market apple is getting crushed in by their competitors, thus losing millions of activations at a growing rate every quarter. This obviously looks bad for future developers and investors.

But as you said, These don't look legit, no matter the price of the phone apple will add the licensing information and device number, there's no way around that. So most likely these are just replicas of the leaked dimensions we've all seen. (Which if you remember pre iPhone 5, even if case makers start making a case based on "guaranteed" specs, apple can always throw a curve ball. )

John Ivy and the rest of apple's design team wouldn't let a sub par product leave the facility, they never have and they never will. Give them some time and I'm sure they won't disappoint. Even a week or two before the last keynote apple didn't have the rights to the music companies for iRadio to be ready just a mere few days before they were able to finalize everything and have it ready to be displayed. Point being, apple will be improving and improving this new line of iPhone until the day it is released. Apple loves wild colors, it's in their roots... This will be their new baby. But of course never forgetting their power users as well.

It's surprising because if these pics do turn out to be real, it's hideous. Apple is and always has been a design centered company. Apple products must function the best in the market and look sexy doing it.

I like the idea of a "lite" iPhone. It's tough to remember here in America that most of the world is still developing their 3G networks. It doesn't make sense to charge them iPhone 5/5s prices for a phone with features they'll never be able to use. Plastic back or not, it'll still have the same Apple quality. I'm actually curious to see how a premium manufacturer like Apple does "cheap". BMW tried it with the 1 Series, and I like those a lot. It could go well!